US3623055A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for indicating disconnection of lighting means in automobile
Assignee: Denso Corp
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Filing: 1969-03-07
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Granted: 1971-11-23
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Expires: 1989-03-07
Abstract
Abstract A device for indicating the disconnection of lighting means in an automobile which insures accurate indication in spite of normal lighting load current variations caused by filament temperature changes, operation sequences, etc. The device includes at least one indicator connected to a power source through a normally closed relay contact that is held open by the normal light load current when there are no disconnected or nonfunctioning lights. The relay coil includes a current coil for carrying the load current and a voltage coil connected in series with a capacitor to cumulatively add to the magnetomotive force of the current coil during an initial period when the light circuit is first switched on to thereby insure an initial opening of the normally closed relay contacts even if some of the light load is disconnected or nonfunctional. In this manner, the normal current variations during the initial period of operation do not cause an erroneous malfunction indication but, rather the current in the current coil after the initial time period is effective to cause accurate malfunction indications.
Inventors
- 👤 Yasuhiko Sakurai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:22
CPC Classifications
B; B60; B60Q; B60Q11/00; B60Q11/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
214 words
A device for indicating disconnection or failure of a lighting means in a automobile, said device comprising: a plurality of lighting means having a normal load current after an initial energizing period, at least one indicator, a normally closed relay contact in series circuit with said indicator and a DC power source whereby an indication is given whenever said relay contact is closed, a current coil means for providing a first electromagnetic force tending to operate said relay contact from the closed position to an open position, said current coil means being connected between said DC power source and said plurality of lighting means, and a voltage coil means for providing a second electromagnetic force in the same sense as said first force also tending to operate said relay contact cumulatively with said current coil means, said voltage means being connected through a capacitor across said DC power source whereby said relay contact is always opened during said initial energizing period, said first electromagnetic force produced by the normal load current of said lighting means after said initial energizing period being sightly larger than the electromagnetic force necessary for holding said relay contact in the open position whereby said indication will be given accurately upon even a slight reduction in said normal load current.
Claim 2
Independent Claim
214 words
A device for indicating disconnection or failure of a lighting means in a automobile, said device comprising: a plurality of lighting means having a normal load current after an initial energizing period, at least one indicator, a normally closed relay contact in series circuit with said indicator and a DC power source whereby an indication is given whenever said relay contact is closed, a current coil means for providing a first electromagnetic force tending to operate said relay contact from the closed position to an open position, said current coil means being connected between said DC power source and said plurality of lighting means, and a voltage coil means for providing a second electromagnetic force in the same sense as said first force also tending to operate said relay contact cumulatively with said current coil means, said voltage means being connected through a capacitor across said DC power source whereby said relay contact is always opened during said initial energizing period, said first electromagnetic force produced by the normal load current of said lighting means after said initial energizing period being sightly larger than the electromagnetic force necessary for holding said relay contact in the open position whereby said indication will be given accurately upon even a slight reduction in said normal load current.
Claim 3
Dependent Claim
52 words
A device as in claim 1 wherein a diode is connected in parallel with said voltage coil means with the forward diode current direction being opposite to the direction of the current normally carried by said voltage coil means to bypass reverse currents in case the DC power source is abruptly reduced.
Claim 4
Dependent Claim
199 words
In a light-load-failure-indicating device comprising normally closed relay contacts connected to an indicator and held open by the normal operating current of a lighting load including a plurality of lighting means connected to a DC power source through a current-sensitive coil of the relay whereby a decrease in lighting load current caused by a light failure of a lighting means causes release and closing of the relay contacts to energize the indicator, an improvement comprising: a series-connected voltage coil and capacitor combinatiOn also connected across said power source, said voltage coil being wound on said relay and connected to produce an electromagnetic force in the same sense as that produced by said current coil whereby for an initial time period, the cumulative electromagnetic forces from said voltage coil and said current coil insure an initial opening of said relay contacts even if some of the lighting load is nonoperative, and said electromagnetic force produced by a normal lighting load current after said initial time period being slightly larger than the electromagnetic force necessary for holding said relay contacts in the open position whereby said indication will be given accurately upon even a slight reduction in said normal load current.
Claim 5
Dependent Claim
199 words
In a light-load-failure-indicating device comprising normally closed relay contacts connected to an indicator and held open by the normal operating current of a lighting load including a plurality of lighting means connected to a DC power source through a current-sensitive coil of the relay whereby a decrease in lighting load current caused by a light failure of a lighting means causes release and closing of the relay contacts to energize the indicator, an improvement comprising: a series-connected voltage coil and capacitor combinatiOn also connected across said power source, said voltage coil being wound on said relay and connected to produce an electromagnetic force in the same sense as that produced by said current coil whereby for an initial time period, the cumulative electromagnetic forces from said voltage coil and said current coil insure an initial opening of said relay contacts even if some of the lighting load is nonoperative, and said electromagnetic force produced by a normal lighting load current after said initial time period being slightly larger than the electromagnetic force necessary for holding said relay contacts in the open position whereby said indication will be given accurately upon even a slight reduction in said normal load current.
Claim 6
Dependent Claim
46 words
A light-load-failure-indicating device as in claim 3 further comprising a diode connected in parallel with said voltage coil and in a sense opposite to the normal direction of current through said voltage coil to bypass reverse currents in case the DC power source is abruptly reduced.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |